In the subsequent couple decades post-World War II, particularly the 1950s and 1960s, the world saw a number of developments on both the nuclear weapons and peaceful use front. On the weapons side, a number of countries, in addition to the US, successfully tested nuclear weapons, including the then-USSR, the United Kingdom, France, and China [1]}. The first thermonuclear weapon, a second-generation nuclear weapon that uses a combination fission and fusion system, was tested in the early 1950s, and soon thereafter widely under development by nuclear weapons states. Notably, however, these weapons intrinsically rely on a fission process [2]}, [3]}, [4]}.
